绿茶中21种黄酮醇糖苷类化合物的鉴别及地理溯源

分析6个产地绿茶中黄酮醇糖苷类化合物种类和含量差异,探究黄酮醇糖苷类化合物对绿茶地理溯源的可行性分析。采用超高效液相色谱-四极杆/静电场轨道阱高分辨质谱（UPLC-Q-Orbitrap HRMS）对黄酮醇苷类化合物进行定性鉴别,建立超高效液相色谱-串联三重四极杆质谱（UPLC-MS/MS）测定绿茶中黄酮醇苷类化合物的定量分析方法。共鉴别出21种黄酮醇苷类化合物,包括5种杨梅素糖苷、8种槲皮素糖苷和8种山奈素糖苷,定量分析结果表明不同产地绿茶中黄酮醇苷类化合物含量存在差异,K-glu-rha-glu含量最高,占总含量的33.1%～57.8%;山奈素糖苷含量最高,杨梅素糖苷含量最低。通过对6个地区绿茶中黄酮醇苷类化合物的差异性及相关性的分析结果可以用于茶叶地理溯源;PCA能有效的区分不同产地的绿茶;BP-ANN识别的准确率为100.0%,且得到2种规范化的重要性为100%的黄酮醇苷类化合物标记物（P<0.05）;PLS-DA模型预测能力为78.2%,筛选出了8种标志物（VIP>1）;LSD模型的整体判别准确率为100%,交叉验证结果准确率为100%。本研究结果为茶叶地理溯源和化...     

杜鹃花色素的分离与鉴定分析

运用特征性颜色反应、高效液相色谱(HPLC)和质谱(MS)等技术对浅红色毛叶杜鹃(R. championae Hook)花瓣花色素提取液进行初步鉴定和含量测定。结果表明：该杜鹃品种的花色素含有非红色的黄酮类化合物,主要有黄酮、黄酮醇、二氢黄酮等色素,其中还有部分酚类色素。高效液相色谱(HPLC)显示杜鹃花色素提取液至少包括39种物质,其中有7种可以确定,分别为杨梅黄素3-半乳糖苷、槲皮素3-半乳糖苷、槲皮素-鼠李糖苷、槲皮素3-葡萄糖苷、锦葵素3-阿拉伯糖苷-5葡萄糖苷、杨梅黄素3-鼠李糖苷、绿原酸。利用紫外分光光度法测得杜鹃花瓣中花色苷的含量为131.025mg/100g,总黄酮含量为10.68mg/g。     

不同产地无糖绿茶饮料滋味特征差异分析

对市售不同产地无糖绿茶饮料滋味品质及其化学成分进行分析比较,以期明确无糖绿茶饮料中的主要滋味物质,探究不同产地绿茶饮料间滋味特征的差异性。结果表明,不同产地绿茶饮料的滋味因子和色差差异不明显,其中日本绿茶饮料的整体滋味品质较优。日本和中国台湾绿茶饮料中茶多酚、咖啡碱、黄酮、可溶性糖质量浓度和儿茶素总量、黄酮苷总量、阳离子总量都明显高于中国大陆绿茶饮料。有13 种化学组分与感官评分相关性较高,其中茶多酚（0.910）、黄酮（0.917）、Mn2＋（0.912）质量浓度与绿茶饮料滋味浓度呈极显著正相关（P＜0.01）;咖啡碱（0.830）质量浓度与绿茶饮料滋味苦度呈极显著正相关（P＜0.01）;牡荆素-2’’-O-鼠李糖苷（Vit-rha）（0.862）、Al3＋（0.811）质量浓度与绿茶饮料滋味涩度呈极显著正相关（P＜0.01）。滋味贡献度（dove-over-threshold,Dot）分析发现黄酮及其苷元对无糖绿茶饮料涩味起主要贡献,包括槲皮素-3-O-芸香糖苷（Que-rut）、山柰酚-3-O-芸香糖苷、槲皮素-3-O-半乳糖苷、槲皮素-3-O-葡萄糖苷、杨梅素-3-O-半乳糖苷、Vit-rha,其中Que-rut的Dot值最高;咖啡碱对无糖绿茶饮料苦味起主要贡献。     

绿茶茶汤中黄酮醇及其苷类的测定方法以及对茶汤色度的影响

黄酮醇及其苷类物质是构成绿茶汤色的重要组分。绿茶中含有20多种黄酮醇及其苷类物质,其中以槲皮素、杨梅素、山柰素的3种苷类物质为主。文中采用高效液相色谱法研究了绿茶茶汤酸水解前后槲皮素、杨梅素、山柰素的含量变化,建立了黄酮醇及其苷类含量的检测方法。利用正交实验方法得到茶汤水解的优化条件为:5 mL的茶汤中加15 mL纯甲醇、5 mL 6 mol/L HCl,在75℃下水解时间2h,芦丁的平均水解率为82.74%。对不同贮藏期间茶汤色度与黄酮醇及其苷类的相关性进行了研究,结果表明:茶汤贮藏过程中随着茶汤的红绿度(a)和黄蓝度(b)不断升高,杨梅素苷含量逐步下降,杨梅素苷与茶汤的红绿度、黄蓝度的相关系数分别为:-0.982 1、-0.882 6,但与茶汤明亮度(L)的相关性不显著。槲皮素和山柰素及其苷类与茶汤色泽变化关系不密切。     

云南丽江和吉林靖宇11种越橘果实花色苷组分的分析

采用高效液相色谱法对云南丽江、吉林靖宇11种越橘果实花色苷组分进行测定。通过标准品的分析,建立了飞燕草素-3-半乳糖苷、飞燕草素-3-葡萄糖苷、矢车菊素-3-半乳糖苷、矢车菊素-3-葡萄糖苷、锦葵色素-3-半乳糖苷、锦葵色素-3-葡萄糖苷的回归方程,相关系数为0.9939~0.9968,精密度RSD为2.00%~3.73%,回收率在98.90%~100.99%,方法准确可行。通过6种标准品的对比,供试的15个样品中,所有越橘品种均有飞燕草素-3-半乳糖苷、矢车菊素-3-半乳糖苷、锦葵色素-3-半乳糖苷3种花色苷,飞燕草素-3-半乳糖苷平均含量为223.99 μg/g、锦葵色素-3-半乳糖苷平均含量为153.34 μg/g,二者占总花色苷的65%。采用欧氏距离聚类分析表明,集群1为飞燕草素-3-半乳糖苷含量较高的三种越橘,代表品种为丽江雷戈西、丽江奥尼尔、靖宇杜克;集群2为6种花色苷总含量较高的越橘品种,代表品种为丽江北陆与靖宇早蓝,说明飞燕草素-3-半乳糖苷含量与花色苷总含量是评价越橘花色苷特点的重要因子。     

茯砖茶中黄酮类化合物的分离与鉴定

本文采用高速逆流色谱与制备液相联用技术分离茯砖茶中黄酮类化合物。高速逆流色谱以正丁醇/乙酸乙酯/乙腈/0.5%乙酸水=12:2:3:15(V/V)为溶剂体系,将茯砖茶提取物分成7个流分,各流分经制备液相分离,获到19个化合物,利用波谱方法鉴定了15个化合物,均为黄酮类化合物:分别为芹菜素-6,8-二-C-β-D-葡萄糖(1),芹菜素-6-C-α-L-阿拉伯糖-8-C-β-D-葡萄糖(2),芹菜素-7-O-β-D-半乳糖-8-C-β-D-葡萄糖苷(3),槲皮素-3-O-葡萄糖-(1-3)-鼠李糖-(1-6)-葡萄糖(4),山奈酚-3-O-β-D-葡萄糖-(1-3)-α-L-鼠李糖-(1-6)-β-D-葡萄糖苷(5),芹菜素-7-O-α-L-鼠李糖-8-C-β-D-半乳糖(6),芦丁(7),山奈酚-3-O-α-L-鼠李糖(1-6)-β-D-葡萄糖苷(8),Camelliquercetiside A(10),杨梅素3-O-β-D-葡萄糖苷(12),异牡荆苷(13),牡荆苷(15),槲皮素3-O-β-D-葡萄糖苷(16),Camelliquercetiside C(17),山奈酚-3-O-β-D-半乳糖苷(18),其中化合物3和6为新黄酮碳苷化合物,化合物1为茶叶中首次发现。     

不同茶类中黄酮醇苷酸水解条件的优化及酸水解前后3种黄酮醇含量的测定

目的 建立高效液相色谱法（High performance liquid chromatography, HPLC）同时测定不同茶类中黄酮醇的含量,并优化茶叶中黄酮醇苷酸水解成黄酮醇（杨梅素、槲皮素、山柰酚）的条件,以此测定不同茶类中三种类型黄酮醇苷元的含量。方法 样品经70%甲醇水（V:V）提取后,用盐酸（16%）-甲醇溶液进行酸水解,再经乙酸乙酯萃取、浓缩、复溶至相同体积;酸水解前后的样品溶液均用HPLC对黄酮醇进行定量分析并用超高效液相色谱-串联质谱(ultra-performance liquid chromatography-tandem mass spectrometry, UPLC-MS/MS)对黄酮醇苷进行定性分析。 结果 3种黄酮醇在3.125~100 μg/mL的浓度范围内具有较好的线性关系（r2≥0.9976）,优化后的方法的重复性、稳定性、精密度较好（相对标准偏差（RSD）≤4%）。六大茶类中黄酮醇苷的最佳酸水解条件：水解时间为1 h,水解温度为80 ℃,盐酸 (16%)-甲醇溶液最佳比例为1:2 (V:V)。 结论 本研究优化了茶叶中黄酮醇苷酸水解的方法,并利用HPLC测定了六大茶类酸水解前后黄酮醇的含量。方法处理简单、结果准确可靠,适用于茶叶中黄酮醇及其苷类物质的分析。     

响应面法优化黑果腺肋花楸酒酿造工艺及成分研究

以黑果腺肋花楸(Aronia melanocarpa)为原料，通过单因素实验和响应面法优化提取工艺，确定黑果腺肋花楸酒最优工艺条件为：发酵液含糖量21%、发酵温度25.5℃、发酵时间7 d以及酵母接种量0.8 g/L，此时酒精度为8.5%vol，多酚类物质含量为3.580 mg/mL。MS/MS结果显示黑果腺肋花楸中多酚类物质主要有矢车菊-3-O-半乳糖苷、矢车菊-3-O-葡萄糖苷、矢车菊-3-O-阿拉伯糖苷、矢车菊-3-O-木糖苷、槲皮素-3-O-芸香糖苷、金丝桃苷、槲皮素-3-O-葡萄糖苷，其中矢车菊-3-O-半乳糖苷含量最高。气相色谱结果表明，该果酒主要包含12种香气成分,苯甲醇含量最高。     

超高效液相色谱-质谱联用技术解析黑果枸杞超临界CO_2萃取物中黄酮类天然产物结构

以青海柴达木黑枸杞为研究材料,对其超临界CO2萃取物,采用超高效液相色谱-质谱联用技术和PeakView色谱工作站拟合进行分析,并通过二级质谱解析和紫外光谱及质谱数据比对,阐明其中的黄酮组分及其结构。共鉴定出黑果枸杞果的超临界CO2萃取物中含有13种黄酮类化合物(7种黄酮醇苷元及黄酮醇苷,3种二氢黄酮醇苷元,2种黄酮苷元和1种二氢黄酮苷元),包括芦丁、槲皮素-3-β-葡萄糖醛酸苷、金丝桃苷即槲皮素-3-O-吡喃半乳糖苷、二氢槲皮素、二氢异鼠李素、二氢山柰酚、槲皮素、芹菜素、橙皮素、苜蓿素、山柰酚、异鼠李素和山柰素,其中橙皮素和苜蓿素在黑果枸杞成分研究中未被发现过。     

HPLC法同时测定枣叶中5种黄酮的含量

建立了一种枣叶中黄酮类成分定量分析的HPLC方法,并对14个品种的大枣及酸枣叶中这5种黄酮的含量进行了分析。结果得到采用Hypersil BDS C18色谱柱,以乙腈与0.1%甲酸水溶液为流动相梯度洗脱,流速1 m L/min,柱温30℃,检测波长360 nm,实现了槲皮素-3-O-洋槐糖苷、芦丁、槲皮素-3-O-β-D-葡萄糖苷、山奈酚-3-O-芸香糖苷、槲皮素-3-O-α-L-阿拉伯糖-(1→2)-α-L-鼠李糖苷5种黄酮苷的同时检测,最低检出限为1.44~2.59μg/m L,加标回收率在93.8%~105.9%之间。5种黄酮苷的含量测定结果表明不同品种的枣叶中黄酮类成分的组成和含量差异较大,其中芦丁和槲皮素-3-O-洋槐糖苷的含量较高,平均为7.83 mg/g D.W和4.61 mg/g D.W;8个品种枣叶中检测到槲皮素-3-O-α-L-阿拉伯糖-(1→2)-α-L-鼠李糖苷,平均5.32 mg/g D.W;而槲皮素-3-O-β-D-葡萄糖苷和山奈酚-3-O-芸香糖苷的含量较低,分别为0.14 mg/g D.W和0.41 mg/g D.W。     

Effect of gamma irradiation on flavonoids in strawberries

In unirradiated strawberries, in addition to ellagic acid, five flavonoids were identified by comparison to standards by reversed-phase chromatography with diode-array detection: (+)-catechin, (-)-epicatechin, kaempferol-3-glucoside, quercetin-3-glucoside and quercetin-3-galactoside. Four others were classified on the basis of UV spectra: two as kaempferol-, one as quercetin- and one as ellagic acid derivatives. Whereas the concentrations of the quercetin- and ellagic acid derivatives were not affected by irradiation, those of the catechin and kaempferol components diminished noticeable. The most significant reduction as a function of dose was found for (+)-catechin, followed by kaempferol-3-glucoside and (-)-epicatechin. Their decreases are, however, in the same order of magnitude as the variation of their concentrations in different harvests and varieties. For two as yet unclassified compounds, characteristic changes upon radiation were observed. The level of one of them is almost quintupled at a dose of 6 kGy.     

Flavonol Glycosides in Cranberries

SUMMARY The yellow flavonol glycosides were isolated from cranberries ( Vaccinium macrocarpon , Ait.) and identified by chromatographic, chemical, and spectral studies. The major pigment was quercetin-3-galactoside, followed by quercetin-3-hamnoside, quercetin-3-arabinoside, quercetin, myri-cetin-3.arabinoside, and myricetin-3-digalactoside.     

Changes of flavonoid content and antioxidant capacity in blueberries after illumination with UV-C

The levels of flavonoids in blueberries (Vaccinium corymbosum L.) were found to increase after illumination with UV-C. Phytochemicals affected included resveratrol, myricetin-3-arabinoside, quercetin-3-galactoside, quercetin-3-glucoside, kaempferol-3-glucuronide, delphinidin-3-galactoside, cyanidin-3-galactoside, delphinidin-3-arabinoside, petunidin-3-galactoside, petunidin-3-glucoside, petunidin-3-arabinoside, malvidin-3-galactoside, malvidin-3-arabinoside, and chlorogenic acid as analyzed by HPLC. Significantly higher antioxidant capacity was detected in fruit treated with 2.15, 4.30, or 6.45 kJ m⁻² compared to the control fruit. UV-C dosage of 0.43 kJ m⁻² also increased phenolics and anthocyanins, but to a lesser extent. The optimum doses of UV-C for enhancing phytochemical content in blueberries were 2.15 and 4.30 kJ m⁻². These data suggest that proper use of UV-C illumination is capable of modifying the phytochemical content of blueberries. Time course measurements of the effects of UV-C revealed that the strongest responses of fruit to UV-C treatment occurred instantly after the illumination and the effects diminished with time. Therefore, even though residual effects were evident following UV-C exposure, the best results were obtained immediately after the treatment.     

Isolation of specific cranberry flavonoids for biological activity assessment

Characterisation of cranberry compound biological activity is constrained by limitations in isolation methodology. A single rapid procedure for polyphenolic isolation was developed using semi-preparative-HPLC. Non-flavonoid compounds were removed by pre-purification procedures prior to semi-preparative-HPLC. Fractions were analysed to ascertain purity (99%) with HPLC and ESI mass spectrometric detection in negative ion mode and on-line diode array ultraviolet–visible spectroscopy. Isolated cranberry flavonols included quercetin-3-galactoside, quercetin-3-glucoside, quercetin-3-rhamnoside, myricetin-3-galactoside, myricetin-3-arabinofuranoside, and quercetin-3-O-(6″-p-benzoyl)-β-galactoside. Proanthocyanidin isolates contained monomers, dimers, trimers, and larger polymers. Anthocyanins consisted largely of galactoside and arabinoside conjugates of cyanidin and peonidin. Identities were confirmed using 1D-NMR- and 2D-NMR-spectrometry as well as reference standards. Flavonol fractions exhibited the highest antioxidant activity in a dosedependent manner, while the anthocyanin fraction exhibited the least activity. Biological activity studies of cranberry phenolics will benefit from the improved isolation procedures described in this study and the confirmation of antioxidant activities of various cranberry constituents.     

LC-MS–MS characterisation of curry leaf flavonols and antioxidant activity

Curry leaf (Murraya koenegii) is a common flavouring agent in Indian foods. This study characterised the flavonol profile of curry leaf extracted with different solvents and the relative antioxidant capacity of these extracts by quantifying phenolic constituents. Flavonols were extracted using ethanol, methanol, or acetone prior to identification and quantification using liquid chromatography coupled to atmospheric pressure chemical ionisation (APCI) mass spectrometry in tandem mode (LC-MS–MS) with negative ion detection. Major curry leaf flavonols included myricetin-3-galactoside, quercetin-O-pentohexoside, quercetin-3-diglucoside, quercetin-3-O-rutinoside, quercetin-3-glucoside, quercetin-3-acetylhexoside, quercetin-O-xylo-pentoside, kaempferol-O-glucoside, and kaempferol-aglucoside. Lag-time and TBARS tests demonstrated that curry leaf phenolics prevent cupric-ion induced oxidation of LDL. The best extraction yield was obtained with 80% ethanol. Acetone extracts provided better antioxidant activity expressed as increased lag-time formation, than did ethanol or methanol extracts. Curry leaf is a rich source of flavonols that have biological activity in vitro and further studies are warranted in regards to the potential health benefits and identification of the novel flavonols whose identities remain unknown.     

A study of polyphenols in the seeds and leaves of guar (Cyamopsis tetragonoloba L. Taub)

Gallotannins, gallic acid, gallic acid derivatives, myricetin-7-glucoside-3-glycoside, kaempferol-7-glucoside-3-glycoside, kaempferol-3-rutinoside, kaempferol-3-glucoside, chlorogenic acid, caffeic acid and ellagic acid were derived from guar seeds and identified by chromatographic and spectral analysis. Myricetin-7-glucoside-3-glycoside, kaempferol-7-glucoside-3-glycoside, kaempferol-3-rutinoside, kaempferol-3-glucoside, quercetin-3-rutinoside, 2,3,4-trihydroxybenzoic acid, texasin-7-O-glucoside, daidzein-7-O-glucoside, chlorogenic acid and p-coumaryl quinic acid were found in guar leaves. The polyphenolic content of guar seeds depended on the stage of maturity varying from 1.26 to 0.69% total phenols; 0.49 to 0.12% gallic acid; 0.5 to 0.21% gallotannins; and 0.13 to 0.23% flavonols (all as percentage dry matter). The polyphenolic content of guar leaves varied from 0.74 to 1.24% total phenols; 0.18 to 0.84% flavonols; and 0.05 to 0.24% hydroxycinnamic acids in the dry matter of guar leaves.     

FLAVONOL GLYCOSIDES OF THE CULTIVATED STRAWBERRY

SUMMARY— Alter extraction and separation by thin-layer chromatography (TLC) on cellulose, nine flavonol glycosides were detected and purified in the fruit of strawberry from various sources. The structures of these were investigated by TLC, spectral properties and several types of hydrolysis. Four of them mere completely identified as the -3-ß-monoglucosides and -3-ß-glucuronides of quercetin and kaempferol. Three others were characterized less fully as kaempferol-7-monogluco-side, a kaempferol-7-glucoside and an unreported quercetin-3-glucoside which was not the -3-ß-monoglucoside or a diglucoside. A comparison between the flavonol glycosides and anthocyanins of this fruit was made with respect to the amounts and types present.     

Phenolic Compounds from the Leaves of Vitis labrusca and Vitis vinifera L. as a Source of Waste Byproducts: Development and Validation of LC Method and Antichemotactic Activity

The cultivation of Vitis (Vitaceae) grape varieties is one of the most important economic activities in agribusiness in southern Brazil. Vitis varieties are rich in polyphenolic compounds with several pharmacological and biological activities, such as antioxidant action. In this context, this study analyzed qualitatively and quantitatively the anthocyans and flavonoids found in the leaves of grape varieties Vitis vinifera and Vitis labrusca. For this purpose, vine leaf extracts were prepared and the chemical profile of each was characterized by LC/MS-MS. Two high performance liquid chromatography-validated methods were performed using UV/VIS-LC-DAD detector to quantify phenolic compounds. The main anthocyanins isolated from vine leaves were cyanidin-3-O-glucoside and peonidin-3-O-glucoside. The flavonoids identified were rutin, quercetin-3-O-galactoside, quercetin-3-O-glucoside, and quercetin-3-O-glucuronide, which was the predominant compound. The Waters X-Terra® RP18 column allowed the effective separation of quercetin-3-O-glucuronide from the other flavonoids for the first time, besides the partial separation of quercetin-3-O-galactoside from quercetin-3-O-glucoside. Furthermore, another phenolic compound was confirmed by MS spectrometry, using direct infusion, as being trans-caftaric acid. The present study also investigates the antichemotactic activity in vitro of grape crude extracts, fractions, and isolated compounds. It was demonstrated that almost all fractions and isolated compounds showed increased antichemotactic effect in response to LPS with a more pronounced values of IC₅₀ for anthocyanins fraction, rutin, quercetin-3-O-galactoside, and trans-caftaric acid (0.9, 1.6, 3.7, and 5.1 ng/mL, respectively).     

基于UHPLC-Q-TOF/MSE技术分析武夷岩茶的化学成分

利用超高效液相色谱-四极杆-飞行时间质谱法（UHPLC-Q-TOF/MSE）结合UNIFI数据分析平台在线鉴定了武夷岩茶中104个化合物,包括茶多酚、茶色素、生物碱、氨基酸和脂质。通过主成分分析（PCA）及正交偏最小二乘判别分析（OPLS-DA）发现了水仙和肉桂的化学成分具有明显差异,并筛选出19个显著差异性成分,其中水仙样品中表儿茶素、槲皮素-3-O-葡萄糖基-鼠李糖基-(对香豆酰基-阿拉伯糖基)葡萄糖苷、茶黄素-3-没食子酸酯等成分的相对含量较高;肉桂样品中5-O-对香豆酰基奎宁酸、表没食子儿茶素-3-O-(3-O-甲基)-没食子酸酯、杨梅素-3-O-半乳糖苷、山柰酚-3-O-葡萄糖苷等成分的相对含量较高。此方法可用于区分水仙和肉桂成品茶。该研究了解了武夷岩茶的化学组成并阐明了其两个主栽品种水仙和肉桂的化学成分差异性,对合理开发武夷岩茶的食用及药用价值具有指导意义,为武夷岩茶品种的鉴别提供科学依据。